In a conventional automobile construction, a filler tube extends through an opening in the fuel tank. A resiliently deformable annular seal is provided around the tube between the latter and the tank. Although the seal is deformable, it is comparatively stiff and uncompressible and is provided with an interference fit between the tube and tank that makes its assembly difficult.
An object of the invention is to provide an improved method for assemblying the seal with the tube and tank wherein the seal is assembled first with the tank and thereafter the filler tube is forced coaxially through the annular seal, thereby to compact the seal radially between the tube and tank to effect the desired sealing engagement.
The seal for which the tool is provided is described in more detail in copending application Ser. No. 715,962, filed Aug. 19, 1976, and is specifically designed to be highly resistant to leakage in the event of deformation of the tube or tank or relative displacement therebetween resulting from collision, especailly a rear end collision at impact speeds up to 30 miles per hour.
Specifically the seal comprising an annular body of resiliently deformable material. When assembled with the tube and tank, the radially inner and outer circumferential portions of the body are deformed and clamped respectively in fluid sealing relationship between the tube and the edge of the tank that defines the tank opening through which the tube extends. The minimum diameter of an inner circumferential portion of the seal body in its undeformed condition is less then the outer diameter of the tube. The diameter of the outer circumferential portion of the undeformed body overlying the aforesaid minimum inner diameter is greater than the diameter of the tank opening and defines the base of a radially outwardly opening annular sealing groove coaxial with the body and having the edge of the tank opening confined therein. Thus the radially inner and outer annular portions of the deformable body are resiliently deformed and pressed toward each other between the tube and tank to effect the seal.
The aforesaid annular sealing groove is defined by axially spaced interior and exterior sides, the interior side extending radially outwardly beyond the exterior side and being inclined toward the latter in the undeformed condition to effect an annular radial seal having an interference fit with the interior wall of the tank around said opening. Also extending into the tank around the tube from the radial seal is a tubular seal of endwise decreasing diameter in the undeformed condition less than the external diameter of the tube to effect an interference fit and sealing engagement therewith. The tubular and radial seals comprise two sealing areas and are sufficiently thin and flexible to yield readily against the tube and interior wall of the tank respectively when subject to the fluid pressure in the tank, thereby to increase the sealing engagement as the fluid pressure increases.
The annular body of the seal also comprises an annular radially inwardly opening fuel entrapping groove or channel located axially outwardly of the sealing groove. The latter channel is defined by an annular channel base having an outer radius smaller than the outer radius of the aforesaid interior radial seal and axially spacing the annular sides of the latter channel, which sides terminate radially inwardly in sealing engagement with the filler tube when assembled therewith.
Another object of this invention is to provide a tool to facilitate the assembly of the seal with the tank by gripping a peripheral edge portion of the seal which after assembly will be located exteriorly of the tank. The tool has radially outer and inner jaws arranged to grip a section of the base of the fuel entrapping channel. When in use, the jaws extend axially from the exterior of the annular seal to a clamping position whereat a clamping portion of the radially outer jaw engages the radially outer surface of said section. The radially inner jaw has a clamping portion that extends radially outwardly into the fuel entrapping channel toward the radially inner surface of the channel base to engage the aforesaid section thereof in opposition to the radially outer jaw. The tool also comprises handle means selectively operative from the exterior of the seal and tank to clamp the jaws radially toward each other in a clamping action to grip said channel base section therebetween, or to separate the jaws radially for withdrawal from the fuel entrapping channel.
Another object is to provide a method of using the tool for assemblying the seal with the tank prior to assemblying the filler tube comprising first gripping said peripheral edge portion of the seal, i.e., the section of the base of the fuel entrapping channel, then forcing the body of the annular seal edgewise, i.e., transversely of its principal axis, into the fuel tank and completely through the tank opening. Thereafter, while retaining the tool's grip on the base section, the latter is pulled by the tool outwardly from the tank and radially toward an edge portion of the tank opening until the latter edge portion is seated within the sealing groove. The outward pull on the seal is coupled with a twisting motion, whereby the portion of the fuel entrapping groove diametrically opposite the gripped section is cocked or pivoted outwardly of the tank opening about the aforesaid edge portion until the entire annular edge of the opening is seated within the sealing groove and the interior radial seal is sealed against the interior of the fuel tank.
Although the material of the seal is deformable, its thicker portions are also tough and difficult to stretch or bend. Accordingly the seal is preferably dipped in lubricating oil before being inserted through the tank opening. Only the comparatively thin peripheral edges of the annular interior seal or the correspondingly thin interior portion of the tubular seal flex readily under the influence of the fuel pressure within the tank. Except for the lubricating oil, the tool need not be provided with auxiliary means for pushing the seal into the tank or for pulling the exterior channel outwardly through the tank opening in the final stages of assembly of the seal and tank.
When the yieldable seal material is sufficiently resistant to deformation or the interference sealing engagements effect an exceptionally tight fit between the seal and tank, the clamping portions of the outer and inner jaws may comprise radially outer and inner U-shaped or oval clamping members respectively for gripping the base of the exterior channel over an appreciable portion but less than one half of its circumference. In such a situation the inner oval clamping member enters the exterior channel and engages both the base and the axially outer side of the latter. Thus the force of the outward pull and twisting motion on the seal is distributed over a large peripheral portion of the exterior channel. The oval shape of the clamping members is dimensioned so that the clamped seal is distorted to an oval shape having a long diameter and a short diameter, whereby the clamped seal may be inserted edgewise in the direction of the long diameter into the tank through its opening.